The rotary encoder is a rotational displacement of the pulse signal into a stream of digital rotary transducer, these pulses can be used to control the angular displacement, if the encoder strip or in combination with the screw gear together, can also be used to measure linear displacement.
　　After the encoder generates an electrical signal from the speed control is set CNC, programmable logic controller PLC, control system to deal with. These sensors are used in the following areas: machine tools, material processing, motor feedback systems, and measurement and control equipment. In ELTRA angular displacement encoder using a photoelectric conversion scanning principle. Reading system is based on the rotation of the radial indexing plate, the indexing consists of alternating opaque and translucent window windows constructed. 　　　This whole system is irradiated with an infrared light source vertically, so put the image on a plate light projected onto the surface of the receiver, the receiver is covered with a grating, said collimator device, and it has a disc the same window. The receiver's job is to feel the light generated by the change in rotation of the disc, and then converts the light into a corresponding change in the electrical changes. In general, the rotary encoder can also get a speed signal, the signal to be fed back to the inverter, thereby adjusting the output data of the inverter. Symptom: 1, rotary encoders bad (no output), the inverter does not work, it becomes very slow speed, and while the drive protection, display "PG off" ... joint action to work. For electric signal rises to a higher level, without any interference, and produce a square wave pulse, which must be processed by the electronic circuit. Pg encoder connection wiring and parameter vector inverter and encoder pg between the encoder must correspond to the model pg. Generally, the encoder pg model points differential output, open collector output and push-pull output three, the transfer mode signal must take into account the frequency converter pg card interface, so choosing the right card model or set reasonable pg.
　　The encoder is generally divided into incremental and absolute, they kept the biggest difference: in the case of incremental encoders, the location is the number of pulses from the zero position mark the beginning of the calculation to determine, and the absolute